They are called Alnitak, Alnilam, and Mintaka
The proximity of the three stars in the sky is an illusion. In fact, the stars at either end of the Belt, Alnitak and Mintaka, are the closest together in space, Alnitak being a little over 800 light-years away from EARTH, and Mintaka 100 light-years farther off. The central star, Alnilam, is much more distant than either of these, lying on the edge of the Orion Molecular Cloud, more than 1,300 light-years from the Sun. Alnilam is also easily the most massive and luminous of the three stars, so that despite its greater distance it still shines more brightly than its two companions.
Not sure about the distance between eac other
hope i helped
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